Are you using your right hand to fret?  Does your left hand have any more range of motion?  What kind of guitar are you using?  Have you tried other types of guitars?

I can't speak to having those specific problems but I do have tutorials aimed at improving finger strength & dexterity.

Warmup Stretches
https://www.guitartricks.com/tutorial/1525/

Trill Drills
https://www.guitartricks.com/tutorial/1829/

Building Pinky Strength & Dexterity
https://www.guitartricks.com/tutorial/1292/

Hope that helps!